Refrigeration apparatus with lubricant oil handling means



Nov. 26, 1968 A. REITER 3,412,574

REFRIGERATION APPARATUS WITH LUBRICANT OIL HANDLING MEANS Filed Dec. 1, 1966 FIG. 2 2w FIG. 3

l0 l5 L ACCUMULATOR CON DENSER COMPRESSOR COMPRESSOR EVAPORATOR SA FEGUARD EXPANSION VALVE CONDENSER COMPRESSOR EVA PO RATOR CAPILLARY TUBE INVENTOR 7%, ALEXANDER L. REITER I W M, g4 BY JiMZo'm (i ATTORNEYS United States Patent 3 412,574 REFRIGERATION APP ARATUS WITH LUBRICANT OIL HANDLING MEANS Alexander L. Reiter, St. Joseph, Mich., assignor to Whirlpool Corporatien, a corporation of Delaware Filed Dec. 1, 1966, Ser. No. 598,342 11 Claims. (Cl. 62471) ABSTRACT OF THE DISCLOSURE A refrigeration system wherein gaseous refrigerant is conducted to a compressor through a duct. A flow control device is provided for metering into the gaseous refrigerant lubricating oil which is collected in a suitable chamber forming a part of the system. The metering device include a buoyant valve member. In one form of the invention the valve member is adapted to be buoyed by liquid refrigerant but not by the lubricating oil for an improved selective control of the lubricating oil delivery.

This invention relates to refrigerant systems and in particular to means for controlling refrigerant fluid and oil delivery to a compressor in such systems.

In one conventional refrigeration system, refrigerant fluid is compressed by a compressor and subsequently condensed in a suitable condenser for delivery as a liquid to an evaporator wherein vaporization of the liquid effects a heat absorption. The vaporized refrigerant fluid is then returned to the compressor for subsequent recycling as discussed above. At times, however, slugs of refrigerant liquid leave the evaporator without vaporization therein and are delivered to the compressor. Such liquid slug delivery is detrimental to the compressor operation.

Further, oil is added to the system for lubricating the moving parts of the compressor. The bulk of the oil is maintained in the compressor, but a portion thereof is entrained in the refrigerant fluid and, thus, is returned with the fluid to the compressor from the evaporator. It is desirable to meter the delivery of the oil to the compressor, rather than permit the flow thereof in slugs to preclude damage to the compressor.

The present invention is concerned with an improved means for controlling the flow of the refrigerant fluid and oil to the compressor to prevent slugs of refrigerant liquid and oil from being delivered thereto and thereby prevent damage to the compressor and maintain a high level of efficiency of operation of the refrigeration system.

Thus, a principal feature of the present invention is the provision of a new and improved means for controlling fluid flow to a compressor in a refrigeration system.

Another feature of the invention is the provision of such a flow control means arranged to permit substantially only refrigerant vapor and oil to be delivered to the compressor inlet.

A further feature of the invention is the provision of such a flow control means arranged to receive liquid refrigerant and permit the same to vaporize before delivery to the compressor inlet.

A yet further feature of the invention is the provision of such a flow control means including a new and improved valve means for metering into the gaseous refrigerant flowing into the compressor inlet oil collected from the refrigerant fluid.

Another feature of the invention is the provision of such a flow control means wherein the metering means comprises a port opening through a duct through which gaseous refrigerant flows to the compressor inlet and a float operated valve responsive selectively to the pres- 3,412,574 Patented Nov. 26, 1968 ence of the liquid refrigerant or oil for selectively opening and closing the inlet whereby the inlet is closed whenever liquid refrigerant is present thereat to buoy the float.

A further feature of the invention is the provision of such a flow control means wherein the float defines a float valve member having a density greater than the density of the oil and less than the density of the liquid refrigerant.

Another feature of the invention is the provision of such a flow control means defining a passage for flowing of refrigerant fluid and oil to said compressor inlet, means defining a wall extending across the passage and having a main port and a small bypass port for passage of refrigerant fluid and oil therethrough, and valve means for selectively closing the main port whenever liquid refrigerant is present at the upstream side of the wall whereby only a small flow of liquid refrigerant is metered through the bypass port while permitting the main port to remain open when no liquid refrigerant is present thereat.

Still another feature of the invention is the provision of such a flow control means wherein the valve means includes a float having a density greater than that of the oil and less than that of the liquid refrigerant whereby the float is buoyed only by the liquid refrigerant, and means associated with the float for closing the main port only when the float is buoyed by the liquid refrigerant.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIGURE 1 is a schematic flow diagram illustrating a conventional refrigeration system having a flow control means embodying the invention;

FIGURE 2 is an enlarged diagrammatic vertical section of the flow control means embodying the invention;

FIGURE 3 is an enlarged diagrammatic vertical section of a modified form of flow control means embodying the invention; and

FIGURE 4 is a schematic flow diagram having another modified form of flow control means embodying the invention.

In the exemplary embodiment of the invention as disclosed in FIGURES l and 2 of the drawing, a conventional refrigeration system generally designated 10 is shown to include a compressor 11 having an inlet 12. The compressor is arranged to deliver compressed refrigerant fluid to a condenser 13 for delivery through av conventional expansion device 14 in liquid form to a conventional evaporator 15. The refrigerant fluid vaporizes in the evaporator 15 and is returned to the compressor inlet 12 for recompression by the compressor 11. The present invention comprehends the provision of a flow control accumulator 16 in the system 10 between the evaporator and the compressor for controlling the flow of the refrigerant fluid to prevent the delivery of slugs of refrigerant fluid and oil from being delivered to the compressor inlet and effectively assuring the metered delivery of oil with gaseous refrigerant to the compressor inlet.

More specifically, as shown in FIGURE 2, the flow control accumulator 16 may comprise an enclosure 17 defining a closed chamber 18. The refrigerant fluid from evaporator 15 is delivered into an upper portion 19 of the chamber 18 through an inlet tube 20. Gaseous refrigerant in the upper portion 19 of the chamber 18 is delivered therefrom to the compressor inlet 12 through a duct 21 having a U-shaped end 22 disposed within chamber 18 and including an inlet leg 23, an outlet leg 24, and a lowermost bight portion 25. As shown in FIGURE 2, the inlet leg 23 opens to the upper portion 19 of the chamber 18 for receiving gaseous refrigerant and con- 3 ducting it through the Ushaped portion and duct 21 to the compressor inlet 12.

As indicated briefly above, at times the gaseous refrigerant may have entrained therewith slugs of liquid refrigerant. Further, a small quantity of oil is entrained in the gaseous refrigerant and flows therewith through the system. The liquid refrigerant and oil entering the chamber 18 through the tube 20 fall through the chamber 18 to collect in the lower portion 26 thereof adjacent the bight 25 of the duct end 22. The present invention comprehends an improved structure for delivering the collected oil into the duct end 22 in metered quantities for flow with the gaseous refrigerant to the compressor inlet 12.

Further, the invention comprehends means for preventing the delivery of slugs of the liquid refrigerant with the gaseous refrigerant being delivered to the compressor inlet 12. In the illustrative embodiment of FIG- URE 2, this means comprises a valve structure generally designated 27 associated with the tube bight 25. More specifically, the valve structure 27 includes a metering port 28 opening downwardly through the wall of the bight 25 into a downwardly opening housing 29 in which is received a ball valve member 30. Herein, the ball valve member 30 comprises a ball float having a density greater than the density of the oil used in the refrigeration systom 10, but less than the density of the liquid refrigerant therein. Thus, when oil is present at the port 28, the ball valve 30 will sink in the oil to open the port and allow the gaseous refrigerant flowing through the bight 25 to the compressor inlet 12 to draw oil through the metering port 28 for delivery therewith to the compressor. However, when liquid refrigerant is present at the port 28, the ball valve will float in the refrigerant to seat upwardly against the bight wall defining the port 28, thereby to close the port and retain the refrigerant in the chamber 18 for vaporization therein and delivery to the compressor as gaseous refrigerant.

When the level of the collected liquid refrigerant drops and the level of the oil again rises to the level of the port 28, the ball valve 30 will again be spaced below the port 28 permitting the oil to be drawn into the flowing gaseous refrigerant and delivered to the compressor.

Illustratively, where the density of the refrigerant is approximately 1.175 and the density of the oil is approximately .90, the ball valve 30 may be formed of polyethylene -plastic having a density of approximately .96. In the illustrated embodiment, the outer surface of the ball member 30 defines the port closure means. As will be obvious to those skilled in the art, the port closure means and float means may be separate, connected elements.

The invention further comprehends the provision of means for desicating the refrigerant liquid delivered to the chamber 18. More specifically, as shown in FIGURE 3, a liquid filter structure generally designated 31 is provided on the upper end of the inlet tube 20. More specifically, the filter 31 comprises a foraminous funnel member 32 coaxially secured to the tube 20 to open conically upwardly, and a quantity of suitable desiccant filter material 33 within the lower portion of the funnel. Liquid refrigerant and oil overflow from the tube 20 and pass downwardly through the desiccant filter material 33 and outwardly through the foraminous funnel to be collected in the lower portion 26 of the space 18. Thus, the filter 31 effectively removes foreign matter such as rust, scale, metal filings, dirt and water from the refrigerant and oil fluids in the system. Improved operation of the refrigeration system is obtained thereby as a result of the prevention of the foreign matter from serving as a catalyst in chemical changes in the system and in copper plating the compressor surfaces. The elimination of water from the refrigerant effectively precludes the formation of highly corrosive hydrofluoric acid in the system thereby further improving the operation of the system.

Referring now to FIGURE 4, a modified refrigeration system generally designated is shown to comprise a system generally similar to system 10 of FIGURE 1, but having a modified form of flow control device 116 in lieu of the flow control accumulator 16 of system 10. Thus, refrigerant system 119 includes a compressor 111 having an inlet 112, a condenser 113, a capillary tube 114, and an evaporator 115.

The flow control device 116 is schematically illustrated in FIGURE 4 as comprising a portion 117 of the conduit 121 interconnecting the evaporator and the inlet 112 of compressor 111. The portion of the conduit 121 defining the device 116 is enlarged in FIGURE 4 and as shown therein includes a transverse baffie wall 134 defining a main axial port 128 and a small bypass port 135. A ball valve 130 is provided in the device 116 subjacent the baflie wall 134 and is generally similar to ball 30 of device 16 in that it is preferably formed of a material having a density greater than the density of the oil and lower than the density of the liquid refrigerant. Thus, when liquid refrigerant is present at the underside of the baifle wall 134, the ball float 130 will float therein and cause the main port 128 to be closed permitting only a small bypass flow refrigerant through the bypass port 135. When, however, liquid oil is present subjacent the bafiie wall 134, the float 130 will sink therein opening the main port 128 and allowing free flow therethrough to the compressor inlet. If desired, heat energy from the refrigeration system or from the medium which is being refrigerated by the system or from another source may be applied to the conduit 121 between the device 116 and the compressor inlet 112 to vaporize the metered liquid refrigerant passing through the bypass port 135 whereby the refrigerant fluid entering the compressor inlet 112 is effectively maintained as gaseous refrigerant fluid at substantially all times in the operation of the system 110.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the con struction and arrangement may be made without depart ing from the spirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a refrigeration system including a compressor, a condenser, and an evaporator, means for controlling flow of fluid from said evaporator to said compressor to prevent slugs of liquid refrigerant from entering the compressor, comprising:

a fluid receiver connected between said evaporator and said compressor;

a wall member in the receiver:

means forming an opening in the wall member for passage of refrigerant vapor and lubricant to the compressor; and

valve means for closing said opening when liquid refrigerant is present in the receiver, said valve means comprising a ball valve having a density less than that of liquid refrigerant but greater than that of lubricant used in the system.

2. The refrigeration system of claim 1 wherein said wall member includes means forming an orifice for pasin communication with the compressor, an opposite end portion in communication with the receiver to receive refrigerant vapor, and an intermediate portion which includes said means forming an opening for passage of refrigerant vapor and lubricant to the compressor.

3. The refrigeration system of claim 1 wherein said wall member includes means forming an orifice for passage of metered portions of liquid refrigerant to the compressor.

4. The refrigeration system of claim 1 wherein said fluid receiver includes a tube connected to the evaporator having an outlet end above the liquid level in the receiver, and a filter on the outlet end to collect foreign matter in the system.

5. The refrigeration system of claim 4 including desiccant means in the filter for absorbing moisture from the fluids in the system.

6. In a refrigeration system having a compressor having an inlet for receiving refrigerant fluid and oil, the refrigerant being present -both as a liquid and as a gas and the oil having a density less than the density of the liquid refrigerant, apparatus for preventing delivery of continuous slugs of liquid refrigerant and oil to the compressor inlet, comprising:

means defining a closed chamber;

means for delivering refrigerant fluid and oil into said chamber whereby gaseous refrigerant may be received in the upper portion thereof and liquid refrigerant and oil may collect in the bottom thereof to define a variable level upper oil surface;

means defining a passage for flowing the gaseous refrigerant from the chamber to the compressor inlet; and valve means for metering the collected oil into the flowing gaseous refrigerant liquid for delivery therewith to the compressor inlet, said metering means including means for causing oil to be metered into said flowing gaseous refrigerant only when the level of the upper surface of the collected oil is at least at a preselected level and the level of the collected liquid refrigerant is below said level. 7. In a refrigeration system having a compressor having an inlet for receiving refrigerant fluid and oil, the refrigerant being present both as a liquid and as a gas and the oil having a density less than the density of the liquid refrigerant, apparatus for preventing delivery of continuous slugs of liquid refrigerant and oil to the compressor inlet, comprising:

means defining a closed chamber; means for delivering refrigerant fluid and oil into said chamber whereby gaseous refrigerant may be received in the upper portion thereof and liquid refrigerant and oil may collect in the bottom thereof;

means defining a passage for flowing the gaseous refrigerant from the chamber to the compressor inlet; and

means for metering the collected oil into the flowing gaseous refrigerant liquid for delivery therewith to the compressor inlet, said metering means including means for causing oil to be metered into said flowing gaseous refrigerant only when the level of the collected oil is at least at a preselected level and the level of the collected liquid refrigerant is below said level, said metering means comprising a valve having a metering port opening to said passage, means for selectively closing said port, and float means for disposing said port closing means selectively to close said port and open said port, said float means having a density greater than the density of the oil and less than the density of the liquid refrigerant.

8. In a refrigeration system having a compressor having an inlet for receiving refrigerant fluid and oil, the refrigerant being present both as a liquid and as a gas and the oil having a density less than the density of the liquid refrigerant, apparatus for preventing delivery of continuous slugs of liquid refrigerant and oil to the compressor inlet, comprising:

means defining a closed chamber; means for delivering refrigerant fluid and oil into said chamber whereby gaseous refrigerant may be received in the upper portion thereof and liquid refrigerant and oil may collect in the bottom thereof;

means defining a passage for flowing the gaseous refrigerant from the chamber to the compressor inlet;

means for metering the collected oil into the flowing gaseous refrigerant liquid for delivery therewith to the compressor inlet, said metering means including means for causing oil to be metered into said flowing gaseous refrigerant only when the level of the collected oil is at least at a preselected level and the level of the collected liquid refrigerant is below said level; and

means in said chamber for desiccating the liquid refrigerant and oil delivered thereinto.

9. The refrigeration system of claim 8 wherein said delivering means comprises means for delivering the refrigerant fluid and oil into an upper portion of the chamber and said desiccating means is disposed below said upper portion for passage of the liquid refrigerant and oil downwardly therethrough to collect in the bottom of the chamber.

10. In a refrigeration system having a compressor having an inlet for receiving refrigerant fluid and oil, apparatus for preventing delivery of continuous slugs of liquid refrigerant and oil to the compressor inlet, comprising:

means defining a passage for flowing of refrigerant fluid and oil to said compressor inlet; means defining a wall extending across said passage and having a main port and a small bypass port for passage of refrigerant fluid and oil therethrough; and

valve means for selectively maintaining said main port open when gaseous refrigerant or oil are present and closing said main port when liquid refrigerant is present at the upstream side of said wall whereby only a small flow of liquid refrigerant passes through said bypass port while permitting said main port to remain open when no liquid refrigerant is present thereat.

11. The refrigeration system of claim 10 wherein said valve means includes a float having a density greater than that of the oil and less than that of the liquid refrigerant whereby the float is buoyed only by the liquid refrigerant, for closing the main port only when the float is buoyed by the liquid refrigerant.

References Cited UNITED STATES PATENTS Re.17,635 4/1930 Williams 62-83 1,769,113 7/1930 Davenport 62-83 3,084,523 4/1963 Bottom 6-2503 XR MEYER PERLIN, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,412 ,574 November 26, 1968 Alexander L. Reiter It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 27, "includes means forming an orifice for pas-" should read comprises a U-tube having an end portion Signed and sealed this 10th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

